A gestational trophoblastic disease is characterized by abnormal cellular growth of the tissues formed as a result of conception, leading to the development of tumors within the uterus. There are three types of gestational trophoblastic tumors: hydatidiform mole/molar pregnancy, choriocarcinoma, and placenta-site trophoblastic tumor (PSTT). Typically, a gestational trophoblastic disease is diagnosed by ultrasound or a Computerized Axial Tomography (CT) or Magnetic Resonance Imaging (MRI) imaging methods. The key test, however, is the hCG blood test.
hCG (human chorionic gonadotropin) is a hormone that increases during pregnancy and is commonly used to confirm pregnancy and as a marker for gestational trophoblastic disease and germ cell tumors. If a woman is not pregnant but has an increased level of hCG it may indicate the presence of a gestational trophoblastic tumor. hCG levels are often rechecked multiple times if a trophoblastic tumor is suspected, since they are a direct measure of the amount of tumor tissue present.
Typically, treatment for gestational trophoblastic disease includes chemotherapy, surgery and combination chemotherapy, or a combination thereof. The treatment or combination of treatments that is recommended will depend upon the severity of the disease. A gestational trophoblastic disease can be invasive, which will require a more rigorous treatment regimen, or non-invasive, which will not require any of the treatments mentioned above. In fact, when non-invasive or slow growing, none of the above mentioned treatments would be effective since they act on fast growing tumors. However, there is currently no accurate method for distinguishing between invasive and non-invasive gestational trophoblastic disease. Thus, there is a need in the art for a method of diagnosing non-invasive gestational trophoblastic disease in order to spare a patient from undergoing unnecessary treatments used to treat invasive gestational trophoblastic disease.